wilding pines management - pukaki downs. check link below for better version of slides
TRANSCRIPT
PUKAKI DOWNS
At The Epicenter of Wilding Spread
in the Mackenzie Basin
KEY POINT
The Seed-Source MUST be removed
simultaneously with spread control
KEY POINT
Failure to remove the seed source will lead to ever
increasing wilding control costs in the mid to long term and the
potential failure of wilding control strategies
3,723 ha.
Victims of legacy planting in the 1960’sShelter Belt
Current state of mature wilding spread
We are victims of government
planting from the 1960’s
Rapid expansion of wildings on Rhoboro Downs
Rapid expansion of wildings on Rhoboro Downs
Rapid expansion of wildings into central Pukaki Downs
Shelter Belt
Rapid expansion of wildings into central Pukaki Downs
Example of the rapid spread
Red line is property boundary
Photo taken when property was acquired
Scattered outliers are visible, but the huge amount of seed and seedlings in
the ground are not visible
8 YRS LATER
JUST 6 YRS LATER
Dec 2015 – viewed from Southern boundary
looking North
Very mature massive seed-source
1. Wilding problem will continue to grow throughout West Pukaki until seed sources are removed.
2. Seed rain from our neighbours will continue to threaten us.
3. Seed rain from us threatens our property and our neighbours.
4. A closed canopy forest offers the greatest protection from seed rain.
5. Re-engineering our forest, i.e. clearing wildings and replanting with non-spreading species will protect us.
Assumptions of the Strategy
The Strategy
1. Containment.
2. Progressively clear and replant the forest with non-spreading trees over 10 years.
3. “Hold the line” – Clear wildings spread beyond containment lines, visiting/sweeping all areas of our property every 2-3 years.
– Clear and plant containment belts of non-spreading pines around the forest.
SHORTCOMINGS of the STRATEGY
1. The forest is not static, the volume of seed-rain grows over time as the forest grows in density, maturity and height.
4. Conclusion – Effective wilding control requires the removal of the seed source simultaneously with containment.
2. Did not properly consider: a) The ever-growing volume of seed-rain as the forest matures b) The increasing range of spread as the trees grow taller.
3. The sharply rising costs year on year for the removal of the ever-increasing wilding spread and ever increasing density of seedlings outside of the containment lines.
1. Our annual wilding control costs are approx. $400,000.
2. Clearing trees outside of the containment lines is eating up an increasing share of the budget. We clear an average of 700 ha. per year. The number of hectares cleared per man day decreases over time (due to higher density), resulting in increasing cost of clearing over time.
3. At the time of wilding clearing/sweeps, visible trees represent only 1/3 or less of the total volume of seedlings in the ground. Spread control budgets often underestimate the costs needed to re-clear these areas in future years.
Rising Costs of Clearing Spread
2006 2007 2008 2009 2010 2011 2012 2013 2014 20150
5000
10000
15000
20000
25000
30000
35000
40000
45000
2000 15005338
35666899
3486
11251
23574
11651
40997
Lake Tekapo Scientific Reserve
YEAR
Seed
lings
Rem
oved
Graph data thanks to David Scott
David Scott leads an effort to remove wilding seedlings from the Lake Tekapo Scientific Reserve each year.
His records reveal an exponential growth due to increasing seed-rain.
Very young wildings are practically invisible at 3-4
meters making the estimation of the scope of
the problem difficult.
Regrowth from these subsequent generations of young seedlings can be 2-3 times more dense than the initial spread.
A 340 ha. block West of the Twizel River. This wasregrowth in 2011 after clearing/sweeping twice
Regrowth just 3 years later
Rising Costs of Clearing SpreadKey Point
4. An expanding and ever-growing seed-source results in an exponential growth of wilding spread.
Seed spreads up to 40km from source.
Implications for the Mackenzie Basin?
5 & 10 km seed-spread radius from 7 major seed sources.
SEED SPREAD
Underlying map was produced by Rob Young
10 & 20 km seed-spread radius from just the 3 largest seed-sources potentially covers 75% of the Basin
Seed-rain grows exponentially as trees grow in density, maturity and height.
The need to urgently remove seed-sources is essential.
Ferintosh StationPukaki Downs
Our northern boundary
We are clearing our Seed-Source, yet we are exposed to re-infestation from neighboring station
Clearing the seed-source
This area to be cleared and replanted in 2016-17
Replanting to create closed-canopy protection from seed-rain
KEY POINT
Failure to remove the seed source will lead to ever
increasing wilding control costs in the mid to long term and the
potential failure of wilding control strategies
Promising New Wilding Control Methods
1. Removal of Mature Forests – Bulldozer with crushing forestry rollers
BULLDOZER WITH CRUSHER/ROLLER
BURNABLE SLASH FROM CRUSHER/ROLLER
Promising New Wilding Control Methods
2. On younger forests - Heavy discing, pasture intensification, followed by mob-stocking or cropping
1. Removal of Mature Forests – Bulldozer with crushing forestry rollers
HEAVY DISCING 1st PASS
Pastoral Intensification is potentially the cheapest & most effective wilding control method
Successful Discing on Rhoboro & Pukaki Downs
Areas Where an Effective National StrategyCan Impact Wilding Removal
1. Aid with heavy equipment financing in seed-source areas:a. Excavatorsb. Bulldozersc. Forestry rollersd. Heavy discs
Areas Where an Effective National StrategyCan Impact Wilding Removal
2. Re-evaluation of conflicting government policies and rules:
a) Remove the restrictions on burning that effectively remove the use of fire to control wildings. Fires are only permitted at the times of year when they will be least effective
Large windrows of mature trees from 2014-15 clearing ready for burning
We needed a hot burn to destroy scattered seed and seedlings around the windrows.
Burn permits are only granted during the least optimum times to burn, resulting in incomplete burns
Incomplete burn
At optimum times burns are complete and cheaper to manage
2. Re-evaluation of conflicting government policies and rules:
Areas Where an Effective National StrategyCan Impact Wilding Removal
b) Policies on nitrogen loading and water use that prevent the conversion of wilding infested areas into pasture
a) Restrictions on burning
Areas Where an Effective National StrategyCan Impact Wilding Removal
2. Re-evaluation of conflicting government policies and rules:
c) The Mackenzie Basin has been declared an Outstanding Natural Landscape, restricting alternative land uses suitable/ideal for wilding control – e.g. pasture intensification
a) Restrictions on burning
b) Policies on nitrogen loading and water use
Areas Where an Effective National StrategyCan Impact Wilding Removal
3. Government needs to extend the seasonal worker visa program to include wilding control workers.
a. There is a shortage of workers available to work during the wilding control season.
• For the past several years we have run wilding crews. • We have our own training program for these crews. • We use Kiwis, Aussies, Canadians and some WOOFERS.
1. National and local level strategies and funding must involve and incentivize landowners with mature seed sources to deal with their seed source now otherwise there will be a high risk of failure of wilding control strategy.
2. Policies currently being discussed may result in landowners with mature seed source forest taking no action while they wait for future government funding.
3. Funding must be provided now to remove mature seed sources.
Landowners Must Be Incentivized
1. Effective wilding control strategy must focus on seed source removal simultaneously with containment and removal of outliers.
2. Failure to remove mature seed sources will lead to ever increasing wilding control costs in the mid to long term and the potential failure of wilding control strategies.
KEY POINT SUMMARY
Government Help
1. Aid with heavy equipment financing in seed-source areas
2. Intervention to adjust government policies and rules that hinder wilding control efforts:
c) The Mackenzie Basin - an Outstanding Natural Landscape restricting alternative land uses for wilding control. Government should encourage Local Councils to consider control methods which can ultimately protect ONLs.
a) Burning restrictions that hinder wilding control effortsb) Policies on nitrogen loading and water use that prevent
pasture intensification (an effective wilding control method)
Government Help
3. Extend the seasonal worker visa program to include wilding control workers.
1. Aid with heavy equipment financing in seed-source areas
2. Intervention to adjust government policies and rules that hinder wilding control efforts:
